Highlights
Age Groups Seen
- Adolescent
- Adult
Languages
- English
Gender
MaleAbout Guy Mulligan
Biography
Locations
- Cleveland Clinic Main Campus
- 9500 Euclid Avenue, Cleveland, OH 44195
- Get Directions
- Twinsburg Family Health and Surgery Center
- 8701 Darrow Road, Twinsburg, OH 44087
- Get Directions
Education & Board Certifications
Education
- Fellowship: Cleveland Clinic, 2010
- Residency: University of Michigan Health System, 2008
- Medical Education: University of Toledo College of Medicine, 2005
- Undergraduate: College of Wooster, 2001
Board Certifications
- Endocrinology, Diabetes and Metabolism: American Board of Internal Medicine, 2010
- Internal Medicine: American Board of Internal Medicine, 2008
Professional Memberships
Research & Publications
See publications for this provider. (Disclaimer: This search is powered by PubMed, a service of the U.S. National Library of Medicine. PubMed is a third-party website with no affiliation with Cleveland Clinic.)
Industry Relationships
Cleveland Clinic physicians and scientists collaborate with industry to advance medical breakthroughs. These partnerships help commercialize discoveries for public benefit while maintaining scientific integrity. To ensure transparency and minimize potential bias, Cleveland Clinic reviews these relationships and publicly discloses when physicians/scientists receive significant compensation for consulting, serve in fiduciary roles, receive royalties, or hold equity interests related to their work. We manage potential conflicts through approval processes, annual reporting, and targeted management plans.
As of 2026-04-20, Dr. Mulligan has reported no financial relationship with industry that is applicable to this listing.
In general, patients should feel free to contact their doctor about any of the relationships and how the relationships are overseen by Cleveland Clinic. To learn more about Cleveland Clinic's policies on collaborations with industry and innovation management, go to our Integrity in Innovation page.
Public Health Service-Reportable Financial Conflicts of Interest. Cleveland Clinic scientists and physicians engage in basic, translational and clinical research activities, working to solve health problems, enhance patient care and improve quality of life for patients. Interactions with industry are essential to bringing the researchers' discoveries to the public, but can present the potential for conflicts of interest related to their research activities. Click here to view a listing of instances where Cleveland Clinic has identified a Public Health Service (PHS)-Reportable Financial Conflict of Interest and has put measures in place to ensure that, to the extent possible, the design, conduct and reporting of the research is free from bias.
* Cleveland Clinic physicians and scientists subscribe to the guidance presented in the PhRMA Code on Interactions with Healthcare Professionals and the AdvaMed Code of Ethics on Interactions with Health Care Professionals. As such, gifts of substantial value are generally prohibited.
Insurances Accepted
Video
Ratings & Reviews
4.9 out of 5
349 ratings, 79 reviewsThe Patient Satisfaction Rating is an average of all responses to the care provider related questions shown below from our survey. Patients that are treated in outpatient or hospital environments may receive different surveys, and the volume of responses will vary by question.
- 5 out of 5 starsReviewed on 5/11/2026
Dr. Mulligan was very informative
- 5 out of 5 starsReviewed on 5/4/2026
Dr. Mulligan was very attentive, as he made me feel heard. He was proactive in ordering bloodwork/urinalysis. He took his time with me. He has a very good bedside manner
- 5 out of 5 starsReviewed on 4/27/2026
Dr. Mulligan is an excellent physician and listens to your concerns and provides valuable feedback.
- 5 out of 5 starsReviewed on 4/13/2026
Dr. Mulligan listened to my concerns and addressed them.
- 5 out of 5 starsReviewed on 4/6/2026
Very pleased with my doctor
- 5 out of 5 starsReviewed on 4/6/2026
Dr. Mulligan took his time with me and truly made me feel my concerns mattered. I didn''t feel rushed and he made me feel comfortable and heard. I left appointment feeling very grateful to find him!
- 5 out of 5 starsReviewed on 4/6/2026
My experience was beyond my expectations. I''ve been through it this last year of not being heard by my regular doctors, but Dr. Mulligan listened to every word and took my concern and applied his knowledge to where I feel I am finally on the correct path to healing. I appreciate him and his kind staff more than words can say.
- 5 out of 5 starsReviewed on 4/6/2026
Dr Mulligan is the best. Always answers all my questions and is very kind..
- 5 out of 5 starsReviewed on 3/23/2026
Dr Mulligan is a great doctor
- 5 out of 5 starsReviewed on 3/23/2026
Dr. Mulligan was awesome Professional answers all my questions. Explained everything to me. Was concerned and interacted with me.
- 5 out of 5 starsReviewed on 3/23/2026
Dr was very thorough in explaining every step of procedure
- 5 out of 5 starsReviewed on 2/27/2026
Again, Dr Mulligan was excellent he took the time to explain things to me
- 5 out of 5 starsReviewed on 2/27/2026
Dr Mulligan was very informative and explained so much to me.
- 5 out of 5 starsReviewed on 2/24/2026
Dr. Mulligan is very knowledgeable and extremely easy to talk to.
- 5 out of 5 starsReviewed on 1/26/2026
Very professional. Doctor was very knowledgeable. Excellent interaction.
- 5 out of 5 starsReviewed on 1/26/2026
Dr Mulligan was very caring. He listened to my many concerns and I did not feel rushed. He was very thorough in explaining my treatment plan and provided me with a written plan. Dr Mulligan is an exceptional physician that I would refer to anyone needing endocrine services.
- 5 out of 5 starsReviewed on 1/26/2026
I like Dr Mulligan hence why I travel to see him. He is worth it and he knows me.
- 5 out of 5 starsReviewed on 1/12/2026
I am very pleased with the Cleveland Clinic and Dr Mulligan. Always a great experience.
- 5 out of 5 starsReviewed on 1/12/2026
Dr. Mulligan took The time to explain how the thyroid system worked which helped me to understand my problem. He listened to my concerns and gave me feedback which was appreciated.
- 5 out of 5 starsReviewed on 1/12/2026
Dr Mulligan always takes his time and fully explains past, present, and future problems and expectations.
- 5 out of 5 starsReviewed on 1/12/2026
He is a very good doctor, he actually listens to you and helps you.
- 5 out of 5 starsReviewed on 12/29/2025
I always recommend Dr Mulligan
- 5 out of 5 starsReviewed on 12/29/2025
Dr Mulligan is very attentive
- 5 out of 5 starsReviewed on 12/29/2025
Dr. Mulligan was extremely professional, patient, listened to my concerns, and I felt great leaving with a plan. He put me at ease and took time to explain everything we were discussing. You can tell that he truly cares for his patients.
- 5 out of 5 starsReviewed on 12/29/2025
Very pleased with my appointment. Very good impression of Dr. Mulligan.
- 5 out of 5 starsReviewed on 12/10/2025
One of the very best doctors. His learned knowledge & manner were par excellence
- 5 out of 5 starsReviewed on 12/10/2025
Best Doctor I've seen in awhile!
- 5 out of 5 starsReviewed on 12/9/2025
Expecting my first grandchild in December, I asked about receiving a booster of the tetanus. Within 5 minutes, Dr Mulligans nurse had the shot administered to me. They truly are the best!
- 5 out of 5 starsReviewed on 12/9/2025
Dr.Muligan listened to my symptoms and proposed solutions to my problems to better my health and treat my condition.
- 5 out of 5 starsReviewed on 12/9/2025
Dr Guy Mulligan is the best!
- 5 out of 5 starsReviewed on 12/2/2025
Dr. Mulligan & his staff are simply the best there is. EVERYONE should be as fortunate to obtain such good care
- 5 out of 5 starsReviewed on 11/13/2025
Dr. M is a a gem. He genuinely cares for his patients. Best around!
- 5 out of 5 starsReviewed on 11/4/2025
Dr. Mulligan is the best doctor I've ever had.
- 5 out of 5 starsReviewed on 11/4/2025
Dr Mulligan was excellent.
- 5 out of 5 starsReviewed on 11/4/2025
Dr. Mulligan is very good at his job and takes the time to explain things to me and listen to my concerns. Such a nice and caring doctor.
- 5 out of 5 starsReviewed on 11/4/2025
Dr. Mulligan is a compassionate physician who always takes the time to develop lasting care plans with me and explains all of the nuances.
- 5 out of 5 starsReviewed on 10/21/2025
Dr Mulligan is an exemplary physician in every way: knowledgeable, professionalism and human kindness.
- 5 out of 5 starsReviewed on 10/21/2025
Dr mulligan is a great caring doctor
- 5 out of 5 starsReviewed on 10/10/2025
Guy is a caring and helpful doctor. I enjoy working with him.
- 5 out of 5 starsReviewed on 10/10/2025
If you've ever had any thyroid problems, you know that endocrinologists are the absolute worst! They follow a strict protocol which doesn't encompass all of their patients needs and/or symptoms.I am happy to say that Dr. Guy Mulligan is the complete opposite of what I have found for the last 30 years, with endocrinologists. He's very knowledgeable, patient and willing to discuss many options.I have never met an endocrinologist who is as qualified as Dr. Mulligan for my care. I will never have another endocrinologist. He is my endocrinologist for as long as I am breathing on this planet.
- 5 out of 5 starsReviewed on 10/10/2025
Dr Milligan has always been an excellent advocate and has been very helpful to me. He has always been available to me if I have questions.
- 5 out of 5 starsReviewed on 10/10/2025
I only wished I had to wait 2 wks to get an appt. Instead of a month. Dr. Mulligan is heavily booked.
- 5 out of 5 starsReviewed on 10/10/2025
Dr. Mulligan referred me to another specialist for post menopausal symptoms.
- 5 out of 5 starsReviewed on 10/10/2025
Dr. Mulligan was the most kindest doctor I ever met! He took his time reviewing my lab results.
- 5 out of 5 starsReviewed on 10/10/2025
Very nice Dr enjoyed speaking with him about my concern
- 5 out of 5 starsReviewed on 10/8/2025
Dr. Mulligan really listened to me and explained lab testing and ultrasound results. He's a very compassionate and informative doctor.
- 5 out of 5 starsReviewed on 10/8/2025
I cannot say enough great things about Dr. Mulligan. He is very thorough!
- 5 out of 5 starsReviewed on 10/8/2025
Dr. Mulligan was extremely thorough and explained everything.
- 5 out of 5 starsReviewed on 9/26/2025
Wait time to come in as a new patient is very long.Doctor and staff are very kind
- 5 out of 5 starsReviewed on 9/25/2025
Dr. Mulligan took the time to review my medical history before my appointment, had a great bedside manner, and was very prompt in sharing the result and his assessments through MyChart.
- 5 out of 5 starsReviewed on 9/15/2025
Dr. Mulligan is a knowledgeable and professional physician. Great experience with him.
- 5 out of 5 starsReviewed on 9/15/2025
Dr. Mulligan is in demand, so it was understandable that an appointment was scheduled months in advance.
- 5 out of 5 starsReviewed on 9/10/2025
Dr did an excellent job describing procedure and did a great job performing procedure
- 5 out of 5 starsReviewed on 9/10/2025
Great and caring physician
- 5 out of 5 starsReviewed on 9/10/2025
The doctor visit was very good after the logistical mess, which certainly wasn't his fault. Very thorough explained everything very clearly
- 5 out of 5 starsReviewed on 8/12/2025
Appreciated all the information Dr. Mulligan sent in my chart
- 5 out of 5 starsReviewed on 8/4/2025
Dr Mulligan was very informative and knowledgeable with a great bedside manner
- 5 out of 5 starsReviewed on 7/29/2025
I trust Dr Mulligan and credit him with keeping my thyroid & parathyroid issues under control
- 5 out of 5 starsReviewed on 7/29/2025
Dr mulligan appeared to be listening to me talk about my medical concerns. It made me comfortable and not embarrassed about how I have been feeling after my thyroid and para-thyroid surgery.
- 5 out of 5 starsReviewed on 7/15/2025
I really appreciate being able to connect online for appointment. Dr. Mulligan is the BEST! He is very supportive, has wonderful insights and LISTENS to me.
- 5 out of 5 starsReviewed on 7/15/2025
My visit was pleasant and I felt Dr. Mulligan was very thorough and not rushed.
- 5 out of 5 starsReviewed on 7/15/2025
Dr mulligan explains things very well and listens! Going over lab results and scans is a nice touch also.
- 5 out of 5 starsReviewed on 7/15/2025
Dr. Mulligan is top notch.
- 5 out of 5 starsReviewed on 7/8/2025
I have NEVER been to a Doctor who is so caring and extremely humbleDr Mulligan kept persuading me to see a Functional Medicine Drbest move for me with Hashimotoshowever I still see him twice a year and his knowledge and patient care first methodology is absolutely superb!!! There is a reason he Is booked out almost a year In advance!!! He is the best and his patients see it!! God bless you and your practice Dr Mulligan!!!!!
- 5 out of 5 starsReviewed on 7/8/2025
Very Attentive and listened to all my concerns. So glad I have him as a doctor
- 5 out of 5 starsReviewed on 7/1/2025
I am so pleased with the appointment. It was very productive. Dr Mulligan carefully listened to all my questions and answered them all.
- 5 out of 5 starsReviewed on 7/1/2025
It was an amazing appointment. Dr Mulligan was recommended to me by my fertility accupuncturist, Anne Kinchen. Dr Mulligan is very knowledgable, patient, polite, put me at ease, listened to and answered all my questions, he thoroughly looks through all the history and tests, he explains the treatment plan in details and even explained to me how to contact him urgently. I am very happy and I feel that I am in good hands now.
- 5 out of 5 starsReviewed on 6/24/2025
The visit with Dr. Mulligan may be the best visit I've ever had with a doctor. He listens, explains, and gives recommendations.
- 5 out of 5 starsReviewed on 6/24/2025
It's just the 4-6 week wait period for an appointment that is discouraging but Dr. Mulligan was worth the wait!
- 5 out of 5 starsReviewed on 6/24/2025
Can't say enough good about Dr. Mulligan. Have already recommended him to others. He really listened to my history of problems since taking the generic thyroid medicine - a rarity to have someone listen! - and he wasn't hung up on lab numbers like so many drs are. He asked clarifying questions and explained options. One of the best dr's visits I have ever had.
- 5 out of 5 starsReviewed on 6/24/2025
Im very grateful I found Dr. Mulligan. He has helped me immensely. I have recommended him multiple times.
- 5 out of 5 starsReviewed on 6/24/2025
Dr. Mulligan is so kind and cares about my weight journey.
- 5 out of 5 starsReviewed on 6/24/2025
Dr Mulligan was very patient in listening to the history of my thyroid journey.
- 5 out of 5 starsReviewed on 6/10/2025
Dr. Mulligan was very attentive and helpful.
- 5 out of 5 starsReviewed on 6/10/2025
Dr. Mulligan's clinical expertise gives me confidence in his care. He knows me as a patient and is committed to keeping me healthy.
- 5 out of 5 starsReviewed on 6/10/2025
Dr. Mulligan has been the only specialist I've seen that has actually listened to what I had to say and cared about my symptoms. Then ordered bloodwork, to find the root of my symptoms. Due to the professionalism of Dr. Mulligan I'm going to switch my primary care physician to Cleveland Clinic, leaving Aultman all together.
- 5 out of 5 starsReviewed on 6/10/2025
Dr. Mulligan was very caring & kind & listened & explained things so I could understand! Very good man!!
- 5 out of 5 starsReviewed on 6/10/2025
It was super easy to set up the appointment, Dr. Mulligan was super polite and easy to work with.
- 5 out of 5 starsReviewed on 5/29/2025
Dr. Mulligan cares about his patients needs and concerns. He listens and answers each and every question. He thoroughly goes over all the blood tests and compares from the previous visits and years. He orders any additional blood work or tests to continue care to address and resolve or maintain the diagnosis. He is the most amazing and wonderful doctor I have ever had after spending many years, many trials and tests, and even traveling out of state to find out what was going on with me. In 2014 he diagnosed that I had Cushing's Disease, my brain tumor was removed, and I continue my care with him and other Cleveland Clinic doctors now.